Without any proof or reference, just by looking at a cedar tree and its leaves, I claim that this is an ideographic character. The radicals are tree 木 and hair 彡. Hairy tree. Tree with hair. Have a look at some pictures of cedar leaves [1][2][3][4]. Who would disagree? However, how much proof is needed in order to put in an etymology section on this page? I mean - the character is not a phonogram, is it?